A representative for Slate Property Group warned the firm to keep quiet about its impending deal to buy 45 Rivington Street until seller Allure Group could pull off a controversial deed restriction removal, according to a new report from the city’s Department of Investigation.

“Do not discuss this deal,” the unidentified Slate representative wrote in an email dated May 14, 2015, according to the DOI report. “The seller is very concerned that the city and union will find out that [the seller] is in contract to sell at the price that we are buying it which will directly impact his ability to have the deed restriction removed.”

“Once he has it removed,” the representative added, referring to Allure, “we can do whatever we want.”

Just a few days earlier, Slate had entered contract to buy the Lower East Side property known as Rivington House from Allure, the report states. At the time, Allure was in the final stages of getting a deed restriction which limited the property’s use to being a nonprofit health care provider removed. The removal of the restriction, which went through in November, allowed Joel Landau’s firm to complete the sale of the property to Slate and its partners China Vanke and Adam America Real Estate for $116 million.

Representatives for Slate, which is led by Martin Nussbaum and David Schwartz, did not respond to a request for comment. When asked to identify the Slate representative who sent the email, the DOI declined to comment, citing an ongoing investigation.

In February, the new owners announced plans to redevelop the 150,000-square-foot building into about 100 luxury condominiums. Since then, multiple officials, including U.S. Attorney Preet Bharara and New York Attorney General Eric Schneiderman, have launched investigations into the de Blasio administration’s removal of the deed restriction. The DOI’s report, released Thursday, slams the city for a series of sloppy mistakes and indifference surrounding the removal. The scandal is a particularly embarrassing one for a mayor who said during his first campaign that “towering, glitzy buildings marketed to the global elite is not the type of development New Yorkers are looking for.”

It’s not clear if Slate, Adam America and China Vanke are being investigated. And though on July 8, the mayor’s office announced a host of changes to the deed restriction modification process, none of those changes will apply to the Rivington House deal. However, the city’s Department of Buildings on April 5 placed a stop-work order at 45 Rivington Street, citing an “illegal conversion” of commercial space. That order remains in place, records show.